Switching a flow of information from one source to another or from one end user to another is an important function of a transmission or computing system. It was the transistor switch which heralded the computer age. In fiberoptic local area networks (LANs) and in fiberoptic sensor systems, the switching of optical beams or waves has not proven to be easy, even for slow speed by-pass applications. The wave or vector nature of photons and the lossy nature of optical interfaces are the reasons. Unlike an electron stream, the beam angle of incidence is an important factor in the transmission of photons through an interface. The presently available techniques for optical switching are: variously complicated, expensive, lossy, confined to a single mode, temperature and enviromentally sensitive, wavelength selective, bulky, slow and require moving parts. Some of the currently available optical switches are: expanded beam/rotating mirror; moving fiber; polarized beam magnetic rotator; traveling acoustic wave; polarized beam liquid crystal rotator; and an electrically operated Lithium Niobate waveguide; while electrically operated organic polymer waveguides are under development.
It is therefore desirable to provide an optical switch, and optical systems employing the optical switch, and a method of optically switching an optical beam from a one to another position to overcome some or all of the disadvantages of the prior art optical switches. In particular, it is particularly advantageous to provide an optical switch which compared with the state of the art switches is simpler and cheaper and usually with lower losses and crosstalk, and which can be used in single or multimode beams, and which can operate over a wide wavelength range, and is solid state, and is environmentally rugged, and is or can be made temperature insensitive.